Printer mechanisms and drives for the print medium are well known in the prior art. In some of the known printer mechanisms, a separate motor is provided for energizing the first print medium drive and the second print medium drive. In other known prior art, a single motor is utilized to drive both the first and second print medium drive. An example of such a drive apparatus is disclosed in U.S. Pat. No. 4,639,154. Such a drive apparatus utilizes one-way clutches to effect rotation of selectively actuatable drive means for the print medium.
Some of the known prior art suffers from the disadvantage that electromechanical elements are utilized to lock one feedpath when switching to the other feedpath when using the same motor to drive both feedpaths. The electromechanical element, such as a locking solenoid, is necessary to prevent oscillation in the feedpaths due to motor oscillation and to prevent medium movement due to existing forces. Motor oscillation would tend to drive the print medium in both paths if one were not locked and accumulate error in the one path which was not desired to be driven. The use of the known electromechanical elements such as solenoids increases the size and cost of the known printer mechanisms.